The goal of this proposal is to determine whether postnatal maternal care can moderate the effects of prenatal exposure to maternal stress on infant/toddler development. Accumulating data indicate that prenatal exposure to maternal psychosocial stress and stress hormones has lasting consequences for development. In the animal literature, there is evidence that postnatal maternal care can moderate the impact of these prenatal exposures. While there is a large body of human work documenting the critical role that maternal care plays in shaping a variety of developmental outcomes, little is known about whether postnatal care moderates prenatal stress exposures. The proposed project will address this question using a prospective design and objective laboratory observational measures. We have prospective data collected on mother infant/toddler pairs collected serially from 14 weeks of gestation through two years of age. Maternal psychosocial and endocrine indicators of maternal stress were collected five times during the prenatal period. Infant development was assessed four times from 3 to 24- months. The purpose of this application is to obtain funds to score existing digital video recordings of maternal child interactions to determine whether the quality of maternal care (level and stability) moderates the influence of prenatal stress on the development of (i) fearful temperament, (ii) stress regulation, and (iii) cognitive development during the first two postnatal years. Observations of mother-infant/toddler interactions were collected at 3, 6, 12 and 24-months using a standardized protocol to assess the quality of maternal care including evaluation of maternal sensitivity and responsiveness that was developed for the NICHD Early Child Care Research Network. Thus we have the unique opportunity to determine whether both the quality of maternal care and the continuity over the first two postnatal years moderate the developmental consequences of prenatal stress in human infants as it appears to in animal models.